Information transfer and storage devices and methods come in many forms, some of which are more suitable for certain tasks than others. A need to both update "temporary" information and retain and organize related "permanent" information is a common situation in record keeping. "Temporary" information is that which is useful and relevant only over the short run. "Permanent" information is information that retains its usefulness and relevance indefinitely.
In many fields, changing conditions or rapid technological change generate a need to transfer and update information regarding new technologies, materials, and processes. At the same time, there is the need to retain permanent records indicating which technologies, materials, and processes have been used in the past.
For example, in the medical sciences there is the need to frequently update information regarding new medicines and medical treatments. There also is the need to preserve permanent records indicating which medicines and treatments have been administered in the past. Similarly, in engineering there is the need to update information regarding new production materials, technologies, and processes while retaining permanent records indicating the materials and processes used previously.
There also is the need in many situations to separate temporary and permanent information so that the temporary information can be discarded after its usefulness has ended, and to prevent it from accumulating and interfering with access to intermingled permanent records. This problem is compounded when numerous loose papers are involved. For example, a practicing physician who maintains permanent records on a patient's health history may also wish to attach temporary information such as upcoming office appointments, outstanding bills, and notes for creating dictated correspondence. Unless this temporary information were removed, it could quickly build up and bury important permanent information and other germane temporary information. Providing for quick reference to permanent written records, portability of records, and ease of recording also are problematical.
These problems are faced by many interests and professions that experience situational or technological change, and that employ "hard copy" primed and written records.